In general, the present technology disclosed in this specification relates to a head mount display which a user mounts or wears on the head to view a video picture, and also relates to a method for controlling the head mount display. More particularly, the present technology relates to a head mount display and a controlling method thereof adapted to prevent occurrence of an incorrect operation when the user is not wearing the head mount display.
A display apparatus mounted or worn on the head of the user to watch a video picture, that is, the so-called HMD (head mount display) is widely known. The head mount display includes an optical unit for each of the left and right eyes, and is configured to control the visual sensation and the auditory sensation of the user in use with headphones. If the head mount display is configured so as to completely shield the user against the external world when the head mount display is mounted on the user's head, the virtual reality can be increased when the user is viewing a video picture reproduced by a BD (Blu-ray Disc) or the like. In addition, the head mount display is also capable of displaying different video pictures to the left and right eyes. Thus, if images with disparity are displayed to the left and right eyes, a 3D image can be presented.
The head mount display has display sections for the left and right eyes. As the display sections, a display panel having a high resolution can be used. Examples of the display panel having a high resolution are panels formed of a liquid-crystal element or an EL (Electro-Luminescence) element. Further, if a proper field angle is set in an optical system and multiple channels are reproduced by the headphones, the realistic sensations like ones experienced in a theatre may probably be reproduced.
Normally, the main body of a head mount display is provided with a UI (user interface) operation section which handles operations carried out by the user. Here, the operations carried out by the user include operations on a reproduction apparatus such as a BD player; for example, reproduction, termination, fast-forwarding, fast-rewinding, volume adjustment of the headphones, and so on. The UI operation section is provided with buttons to be operated by the user in order to carry out those user operations. While the user is watching a video picture reproduced by the BD player with the head mount display, the user carries out controls from reproduction to termination, and the user may also adjust the volume to a proper level through the UI operation section.
Generally, even after the user had taken off the head mount display from his or her head, the audio continues to be output from the headphones at a volume at which the user had had set through the UI operation section. This is similar to other AV (Audio-Visual) apparatus that an audio is continuously output from the headphones even while the user is away from the apparatus.
However, while the head mount display is dismounted from the user's head, due to an external factor such as an erroneous operation or application of weight, the “+” button of the volume may be pressed for a long time, that is, pressed in a way that the volume increases. As a result, the volume may reach the maximum level without the user noticing it.
Later on, when the user again wears the head mount display in order to resume viewing, there is a fear that the user hears a detonating sound which may cause an auditory disorder or health damage related to auditory sense.
For example, Japanese Patent Laid-open No. Hei 11-174991 discloses a head mount display configured to prevent an incorrect operation between a select switch and a confirm switch by setting the operation direction of the confirm switch, a switch for confirming various screen settings and volume setting, at 90 degrees from the operation direction of the select switch. Even though this head mount display is designed to prevent the user from carrying out an incorrect operation while the user is watching a video picture, that is, wearing the head mount display, it is not configured to prevent occurrence of an incorrect operation when the user is not watching a video picture, that is, not wearing the head mount display due to an external cause. To be more specific, if a setting operation is carried out at two stages, for example a select operation stage and a confirm operation stage, the head mount display can prevent incorrect operation. However, if a setting operation is carried out at one stage, for example by operating a “+” or “−” button, the head mount display cannot prevent incorrect operation. In addition, it is a complicated operation for the user to carry out setting at two stages of a select operation stage and a confirm operation stage.